Question

1. draw the free body diagram of the scenario: a rightward force is applied to a large box to push it across the horizontal, rough floor at a constant speed. ignore air resistance.

Explanation:

Step1: Analyze the forces

When the box is pushed at a constant speed, according to Newton's first law, the net force on the box is zero. In the vertical direction, the normal force \(F_{normal}\) balances the gravitational force \(F_{gravity}\), so \(F_{normal}=F_{gravity}\). In the horizontal direction, the applied force (rightward force here) should balance the frictional force \(F_{friction}\), so \(F_{applied} = F_{friction}\).

Step2: Check each diagram

• Diagram A: There is no frictional force shown, which is wrong as the floor is rough.
• Diagram B: The right - ward force is labeled as tension, which is incorrect as the problem states a rightward applied force.
• Diagram C: The normal force and gravitational force are not balanced (the labels are wrong for vertical forces).
• Diagram D: In the vertical direction, \(F_{normal}\) and \(F_{gravity}\) are balanced (\(F_{normal}=F_{gravity}\)), and in the horizontal direction, \(F_{applied}\) (right - ward) and \(F_{friction}\) (left - ward) are balanced (\(F_{applied}=F_{friction}\))

Answer:

Diagram D